Processes for alkylating a variety of alkylatable aromatic compounds by contacting such compounds with a hydrocarbon radical providing source such as an olefin or alcohol are widely known. Typically, alklatable aromatic compounds are mononuclear aromatic compounds themselves or those substituted with a hydroxyl, a mine or an ether group. The alkylation has been carried out in the presence of homogeneous and heterogeneous catalyst systems.
Representative references which illustrate some of the early processes in forming ring alkylated aromatic amines are:
British Patent 414,574 discloses the reaction of aniline with various olefins, e.g., cyclohexene and alcohols, e.g., butanol in the presence of a neutral or weakly acidic catalyst system commonly referred to as hydrosilicates at temperatures from 200.degree.-270.degree. C. Ortho and para-cyclohexylaniline, N-cyclohexylaniline, N-butylaniline and para-methyl-ortho-cyclohexylaniline and N-cyclohexyl-para-toluidine are listed as representative products.
British Patent 846,226 discloses ring alkylation of aromatic amines with olefins using active, substantially neutral bleaching earths of the montmorillonite type as a catalyst.
As 1,051,271 discloses the ring alkylation of aniline with an olefin, e.g., ethylene, in the presence of kaolin or in the presence of aluminum and aluminum alloys. Alkylation with higher olefins, e.g., propylene, butylene, etc., was carried out in the presence of Friedel-Crafts catalysts or bleaching earths under liquid phase conditions at temperatures from 150.degree.-350.degree. C. Representative examples of operable catalytic systems including aluminum chloride, zinc chloride, boron trifluoride, sulfuric acid, phosphoric acid and bleaching earth. Ring alkylation at the ortho-position was predominant, although other products such as the di and tri-alkylated aniline product were produced.
Netherlands Application 6,407,636 has recognized that alkylation of various aromatic and heterocyclic compounds can be carried out in the presence of a zeolite having a pore size from 6-15 Angstroms wherein active cationic sites are obtained with an exchangeable metal or hydrogen cations in their ordered internal structure. Alkylating agents include olefins having from 1 to 12 carbon atoms, alkyl halides such as propyl bromide and ethyl chloride; and alkanols, such as, methanol, ethanol, and propanol. Various compounds were suggested as being suited for alkylation and these include both the heterocyclic and aromatic ring compounds. For aromatic amine alkylation it was suggested that a zeolite with a disperse distribution of acid sites should be utilized. It was believed the highly acidic zeolite catalysts which have a high density of acidic sites may bind the amine to the catalyst and block the pore structures. In Example 1, aniline was alkylated with propylene using sodium zeolite X having a pore size of 13 Angstroms and numerous alkylated amines were produced. Example 3 shows alkylation of diphenylamine with cyclohexene using a rare earth exchanged 13.times. zeolite. Again, numerous ring alkylated products were produced and high temperatures, e.g., 300.degree. C. and above apparently being required to weaken the amine-acid bond.
French Patent 1,406,739, which is equivalent to Netherlands Application 6,407,636, discloses the preparation of alkylated aromatic compounds having polar substitutions thereon utilizing alumino-silicates having a pore size of at least 6 Angstroms as a catalyst. Cations of low valence were deemed to have been particularly effective for the ring alkylation of aromatic compounds having weakly basic substituents such as aromatic amines. The examples show the alkylation of aniline with propylene in the presence of a sodium zeolite X and alkylation of diphenylamine with propylene in the presence of a molecular sieve 13.times. which has undergone a partial exchange with rare earth metals and having a pore size of 13.ANG..
U.S. Pat. No. 4,745,223 discloses the preparation of tert-alkyl toluenediamines and other aromatic amines by reacting an olefin with an aromatic amine in the presence of a highly acidic crystalline alumino-silicate. Examples of aromatic diamines include tert-butyl-toluenediamine.
U.S. Pat. No. 3,670,030 discloses the alkylation of a phenolic compound with an olefin in contact with an alumina catalyst. To prevent deactivation of the catalyst, water was added to the reaction zone in a controlled amount, e.g., from about 500-3000 ppm based upon the phenolic compound.
U.S. Pat. No. 3,546,100 shows a process for cracking hydrocarbon feedstocks over a rare earth exchanged crystalline alumina-silicate catalyst. Water addition to the reaction was made in order to control catalyst activity.